The present invention generally relates to displays and more particularly relates to a display system including a printed display and a printed battery integrated together onto a single substrate.
In many applications, such as magazines, advertising, toys, greeting cards, CD jackets, etc, it is desirable to have a low cost, semi-disposable electronic display that can be activated to provide a dynamic motion, figures or games. A number of display technologies can be printed, such as electrochromic displays (e.g., Monsanto Corporation""s interdigitated concept), thermochromic (i.e., xe2x80x9cheat activatedxe2x80x9d) displays and electroluminescent displays, etc. Printing displays can provide a low cost, flat, simple method for production, however, a limiting factor for using these displays is the cost, attachment, storage (shelf life), shipping and handling of batteries used for powering such displays.
Presently, commercial batteries used for these applications tend to be bulky and expensive. For example, coin cell type batteries used in some of these applications can be one-eighth of an inch (xe2x85x9xe2x80x3) or more thick. In addition, the electrical attachment to a display only 0.005 or 0.010 inch thick requires mechanical borders and spring contacts, as well as mounting and hand labor for large batteries. Further, as these devices increase in complexity, they become less reliable. Therefore there is a need in the art for a display system that overcome the shortcomings of the prior art.
The present invention relates to a display system having a printed display integrated with a printed battery to provide an extremely thin, portable display system that may be used in numerous, diverse applications, for example, greeting cards, advertisements, bumper stickers, toys, commercial labels, stamps, etc.
The display system of the present invention overcomes the size limitations of the prior art (primarily the thickness) by integrating a printed display with a printed battery. The printing of both components results in a very thin display system (e.g., about 0.005 to about 0.010 inches) which greatly expands the number of applications for such a display system. In addition, because both components are printed, both components may be integrated onto the same substrate, thus further reducing the size of the display system. The printing of both components also allows printed conductors to interconnect the components which substantially improves the reliability of the connections while reducing the cost of manufacture.
The printing system of the present invention may employ any one of various printed displays. For example, the display may include a printed electrochromic display, a printed thermochromic display, a printed electroluminescent display or a printed electronic ink display, among others. The printed battery may be directly coupled to the printed display or alternatively may be selectably coupled thereto via a switch. The switch may be a touch-type switch which forms a short circuit in response to an external force applied thereto; alternatively, the switch may be an electrically controllable switch, for example, a thin film transistor which serves to activate the printed display in conjunction with a programmable control sequence. Consequently, the display system may form a single pixel or display portion in a larger display environment and, in conjunction with a plurality of such pixels or display portions, may provide a dynamic display capable of generating multiple images.
The printed battery of the present invention is preferably formed in two, separate printed stacks to allow for storage of the display system in a non-activated state. The printed stacks are preferably formed on a single, flexible substrate having a spaced apart anode layer and cathode layer formed thereon. A printed electrolyte layer is formed on either the anode layer or the cathode layer with a release liner formed thereon. Because the anode layer and the cathode layer, when separated, are not in ionically conductive contact with one another through the electrolyte layer, no battery leakage occurs and the printed battery advantageously has a virtually infinite storage life. The printed battery may be activated by removing the release liner and coupling the anode and cathode layers together via the electrolyte layer, preferably by folding the flexible substrate, as has been developed by Wisconsin Label.
The display system of the present invention may be formed by printing with both the printed display and the printed battery formed adjacent to one another on a common substrate with printed conductors formed thereon to establish electrical communication therebetween. It was discovered that many, but not all of the printing materials and printing steps were similar for the printed battery and the display. Alternatively, the printed display and the printed battery may be integrated vertically with the printed display formed on top of the printed battery, thus further reducing the size of the display system. In addition, the printed display and printed battery may be formed in a vertical relationship on opposite sides of a common substrate with the anode layer and cathode layer spaced apart from one another to allow the printed battery to be maintained in a non-activated state. By folding the substrate, the printed battery is activated and forms a vertically coupled printed display system. It was also discovered that one could print touch panel or activation switches at the same time one could print the battery and the display.
To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.